Molten metal sampler



NOV. 28, 1967 5M|TH 3,354,723

MOLTEN METAL SAMPLER Filed April 9, 1965 INVENTOR. WILLIAM F. SMITH hisATTORNEY United States Patent 3,354,723 MOLTEN METAL SAMPLER William F.Smith, Aliquippa, Pa., assignor to Jones &

Laughlin Steel Corporation, Pittsburgh, Pa., a corporation ofPennsylvania Filed Apr. 9, 1965, Ser. No. 446,939 6 Claims. (Cl.73425.6)

This invention relates to apparatus for obtaining a sample of metal foranalytical purposes from a molten bath. It is more particularlyconcerned with apparatus for obtaining a sound rod-like sample of suchmetal.

My invention is particularly adapted for use in the manufacture of steeland will be described in that connection hereinafter. It is, however,suitable for other metals as well.

In the manufacture of steel it is necessary to determine the content ofcarbon and often of other constituents of the melt while it is in themolten state. This requires sampling of the melt. It is conventional tosuck molten steel up into a glass tube of a small uniform cross sectionbore so that it solidifies in the tube which is then broken away fromthe sample so obtained. If a sound sample can be obtained, that is, onefree from internal cavities, then a length of sample corresponding to apredetermined sample weight can be obtained by cutting a section of therod in an appropriate jig. Unfortunately, although the molten steel fromwhich the sample is sucked is usually deoxidized so that there is noevolution of gas therefrom, the steel sucked up into the glass tube inthe conventional way tends to solidify against the wall of the tube butto remain molten in the center. The molten steel then runs back down,leaving a cavity.

It is the principal object of my invention to provide apparatus adaptedto sucking molten metal into a tube of uniform cross section so as toproduce a sound sample. It is another object to provide such apparatuswith easily connectable sample tubes and easily replaceable elements.Other objects of my invention will appear from the following descriptionthereof. I provide my suction device with a chill element in the sampletube dimensioned and positioned to bring about rapid solidification ofthe molten metal throughout its cross section adjacent the chill, andprogressive solidification of the metal therebelow at a rate sutlicientto prevent the running out of metal from the center of the sample. Threeembodiments of my invention presently preferred by me are illustrated inthe attached figures, to which reference is now made.

FIGURES 1, 2, and 3 are elevations in section of first, second and thirdpreferred embodiments of my invention, respectively.

In the figures and the description which follows, elements which arecommon to the various embodiments of my invention are identified by likereference characters. The apparatus as illustrated in FIGURE 1 comprisesa conventional glass sample tube 1 of uniform bore which is connected toa suction tube 4 by a sleeve 3 so as to leave a gap or space of enlargeddiameter 7 between the facing ends of the two tubes. Sleeve 3 is ofrubber or like stretchable material which grasps sample tube 1 andsuction tube 4 tightly, but permits those tubes to be readilydisconnected therefrom and replaced. The end of suction tube 4 remotefrom sleeve 3 is fitted to a bulb 5 of rubber or other collapsibleresilient material. Within the bore of 3,354,723 Patented Nov. 28, 1967"ice sample tube 1 is positioned chill element 2 which is of slightlysmaller diameter than the bore of sample tube 1. Chill element 2 isformed with a projecting flanged end 6 which is disposed in the gap 7previously mentioned.

In the embodiment of my apparatus illustrated in FIG- URE 2, sample tube11 is formed with constricted boreportions 13 and 14 spaced from eachother, and chill element 12, which is cylindrical in shape and ofuniform cross section smaller than the bore of sample tube 14, ispositioned between its constricted portions so that it cannot passbeyond either of them. The apparatus is otherwise the same as thatillustrated in FIGURE 1.

In the embodiment of my apparatus illustrated in FIG- URE 3, the sampletube 21 is fitted with a constricted bore portion 23 spaced from its endwhich is within sleeve 3. Chill 22 is of uniform cross section smallerthan the bore of sample tube 21 and is positioned between constrictedbore portion 23 and suction tube 24. End portion 25 of chill 22, whichextends into sleeve 3, is of smaller cross section than the body of thechill, so as to minimize the heat transferred to sleeve 3. The bore 28of suction tube 24 is smaller than the diameter of chill 22 or,alternatively, is off center, so that chill 22 cannot enter it. It isnot necessary, of course, that suction tube 24 be of this constructionthroughout its length. Only its end portion within sleeve 3 need be soformed, the apparatus is otherwise the same as that of the embodiment ofmy FIG- URE 1.

The operation of my apparatus will be described with reference to theempodiment of FIGURE 1. The operator holds the device by bulb 5,compresses that bulb to drive the air out of it through suction tube 4,sleeve 3, and sample tube 1, then immerses the open end of sample tube 1below the surface of the molten steel. He releases the pressure on bulb5 so creating a suction. Atmospheric pressure on the surface of themolten metal causes metal to enter sample tube 1 and rise until itencounters chill element 2 which effects immediate solidification of themolten metal in contact with it. Chill 2 is kept in place by flange 6which cannot move out of the larger bore gap area 7. When the metal hassolidified in sample tube 1, the latter is disconnected from sleeve 3and broken, which releases the rod-like sample. A predetermined lengthof this sample is then cut and used for analytical determinations. Thechill element 2 is recoverable and can be used again with otherdetachable sample tubes 1.

The operation of the embodiments of my invention illustrated in FIGURES2 and 3 is the same as that of FIG- URE 1 above-described. Chillelements 2, 12, and 22 are conveniently made of copper or other metal ofhigh conductivity. Suction may be provided by means other than the bulb5, for example, a suction pump, or an evacuated container.

I claim:

1. Apparatus for obtaining a sound rodlike sample of metal from a moltenbath thereof comprising suction means, a tube of uniform bore detachablyconnected at one end to the suction means, a chill element in the tube,the chill element cross section being less than that of the bore so thatsuction produced by the suction means draws molten metal into the tubewhen its open end is immersed therein, the chill element cross sectionand length being sufficient to cause molten metal drawn into the tube tosolidify against the chill, and means for positioning the chill elementintermediate the open end of the tube and the suctions means.

2. Apparatus of claim 1 in which the chill positioning means comprises alocalized tube section of enlarged bore and a flange on. one end of thechill element fitting within the enlarged bore, but wider than theuniform bore.

3. Apparatus of claim 2 in which the tube section of enlarged bore is anexternal sleeve detachably connecting the tube and the suction means.

4. Apparatus of claim 1 in which the chill positioning means comprisespaced apart bore constrictions between which the chill element isconfined.

5. Apparatus of claim 4 in which one constriction comprises the end ofthe suction means detachably connected 15 to the tube of uniform bore.

6. Apparatus of claim 1 in which the chill positioning means comprise abore constriction and a localized tube section having a bore eccentricwith respect to the tube of uniform bore between which the chill elementis con- 5 fined.

References Cited UNITED STATES PATENTS 2,970,350 2/1961 Feichtinger. 103,221,559 12/1965 Miller et al. 73425.4

3,309,928 3/1967 Cavalier 73-4256 LOUIS R. PRINCE, Primary Examiner.

DANIEL M. YASICH, Assistant Examiner.

1. APPARATUS FOR OBTAINING A SOUND ROD-LIKE SAMPLE OF METAL FROM AMOLTEN BATH THEREOF COMPRISING SUCTION MEANS, A TUBE OF UNIFORM BOREDETACHABLY CONNECTED AT ONE END TO THE SUCTION MEANS, A CHILL ELEMENT INTHE TUBE, THE CHILL ELEMENT CROSS SECTION BEING LESS THAN THAT OF THEBORE SO THAT SUCTION PRODUCED BY THE SUCTION MEANS DRAWS MOLTEN METALINTO THE TUBE WHEN ITS OPEN END IS IMMERSED THEREIN, THE CHILL ELEMENTCROSS SECTION AND LENGTH BEING SUFFICIENT TO CAUSE MOLTEN METAL DRAWNINTO THE TUBE TO SOLIDIFY AGAINST THE CHILL, AND MEANS FOR POSITIONINGTHE CHILL ELEMENT INTERMEDIATE THE OPEN END OF THE TUBE AND THE SUCTIONSMEANS.